Insecticide



Patented Mar. 2a, 1948 INSECTICIDE .Allen a. Lewis, Berkeley, CaliL,assignor, by K -mesne assignmentatocalifornia Research Corof'Delawareporatlon, San Francisco, Calif., a corporation No Drawing. ApplicationJuly 27, 1943;

Serial no. 496,310

This invention relates to improved insecticidal compositions containingplant extracts, such as pyrethrum and rotenone, in combination witharomatic sulfonamides.

It is well known that certain plant extracts such as pyrethrum,rotenone, etc. have the property of paralyzing and killing many speciesof insects by contact. They are widely used as the toxic element ofinsecticides, usually along with inert material which serves as vehicle,spreader, or diluent, as for example in solution in kerosene.

I have discovered that, although as' a'rule sulfonamides by themselveshave comparatively little toxic eifect, the addition of certainsulfonamides greatly increases the toxicity of these lant extracts. Mydiscovery thus makes possible the production of insecticides of veryhigh potency without the use of prohibitive amounts of costly plantextracts. It also provides a means of reducing the consumption of plantextract without loss of toxic emciency.

The compounds which I have discovered which have the property ofactivating the insecticidal effect of pyrethrum, rotenone, etc., andwhich I refer to as aromatic sulfonamides, are aromatic sulfonic acidamides of the type represented by the following general formula:

in which R4 is a heterocyclic ring containing nitrogen, attached to thesulfur atom by a sulfur to nitrogen bond.

Examples of effective compounds of the type 2 Claims. (Cl. 167-24)Ruphenyl In addition to the above I have found that effective compoundsof this type are those in which R1 is derived from highly aromaticpetroleum fractions or extracts. I have also found that from 1 to 6carbon highly effective sulfonamides are those in which representedabove are those in which the radicals are I R4 consists of reduced(hydrogenated) nitrogen bases such as those obtained from petroleumfractions or from coal tar. The weak bases which .have heretofore beenextracted from light petroleum distillates are of the nature of tertiaryamines. They may be reduced, as by catalytic hydrogenation, to what maybe termed secondary amines. Reduced nitrogen bases as used herein refersto products of this nature. One method of preparing these bases isdescribed in U. S. Patent No. 2,302,655. a

Some of the aromatic sulfonamides typical of those described generallyabove and which have been found to produce an excellent toxic activationoi pyrethrum, rotenone, etc. are: 0- and ptoluene sulfonyl di-n-butylamide; oand ptoluene sulfonyl reduced-nitrogen-base; benzene sulfonylreduced-nitrogen-base; p-toluene sulfonyl methyl p-toluidide; p-toluenesulfonyl tetrahydro quinolide; p-toluene sulfonyl morpholide.

In general the sulfonic acid amides of the type described may beprepared by the reaction of amines or ammonia with sulfonic acidchlorides. The reactants are selected and -combined so as to result in asulfonic acid amide having the indicated general formula. For example,o-toluene sulfonyl di-n-butyl amide may be prepared by reactingo-toluene sulfonyl chloride with di-n-butyl amine.

An example which illustrates the method of preparation of a suitablesulfonamide from an aromatic extract of petroleum and reduced nitrogenbases from petroleum is as follows: 230 parts 190-280 F. boiling rangewere added slowly to' 800 parts of chlorsulfonic acid. The temperatureof the reaction was held at about 40 F. and the mixture stirred for 12hours. The reaction mixture was then poured onto ice. 207 parts ofaromatic sulfonyl chloride separated as a heavy liquid and was washedwith water and dried. 200 parts of reduced nitrogen bases obtained bythe catalytic hydrogenationof nitrogen bases extracted from Californiapetroleum were dissolved in 250 parts of petroleum ether. 100 parts ofthe aromatic sulfonyl chloride were added at a maximum temperature of130 F. and the mixture agitated for 1 hour followed by water washing anddistillation to remove hydrochloric acid and petroleum ether. 130 partsof a heavy red liquid were thus obtained consisting of aromatic sulfonylsubstituted-piperidides.

The following is an example, for illustrative purposes, of aninsecticidal composition using an aromatic sulfonamide in combinationwith pyrethrum according to my invention: 3'parts by volume of p-toluenesulfonyl di-n-butyl am de and 2.5 parts of a 20:1 commercial pyrethrumextract were dissolved in kerosene to a total volume of 100 parts,giving a solution containing 3 per cent by volume of the sulfonamide anda total pyrethrin concentration of 50 milligrams.

per 100 cc. This solution was tested as a spray according to thestandard Feet-Grady large group method on four different cultures offlies. 100% of the flies were paralyzed at the end of ten m nutes and69% were dead at the end of 24 hours.

The effect of the use of the sulfonamide in this spray is clearly shownby the fact that a control spray containing the same amount of pyrethrumin the same kerosene. but containing no sulfonamide, paralyzed 99.7% ofthe flies in minutes while giving only 11.4% kill at the end of 24hours. That the increased toxicity of the comb nation spray was not dueto the additive toxicities of the ingredients is shown by the fact thatakerosene solution containing 3% by volume of p-toluene sulfonyldi-n-butyl amide alone gave zero knock-down in 10 minutes and only 8%kill at the end of 24 hours.

Similarly, the p-toluene sulfonamide from reduced petroleum nitrogenbases, when added in 1 the proportion of 3% by volume to a kerosenecontaining 2.5 percent of a 20:1 pyrethrum extract, raised the 24-hourkill from 13.4% to Addition of this sulfonamide to kerosene containing0.5% by volume of derris root (rotenoid) extract raised the 24-hour killfrom 47.4% to 61.4%. When 3% of this sulfonamide was tested by itself inkerosene it gave only a 6% kill, which is approx mately the resultobtained from the use of highly treated kerosene alone.

In like manner other sulfonamides (in a 2.5% solution of pyrethrum 20:1extract in kerosene) gave the following results:

vol.) kill 88.4 p-Toluene sulfonyl methyl toluidide (3% vol.) --increasein kill..- 63.1

The above data, obtained under the most' rigorous test conditions,exemplify the powerful activating effect of the aromatic sulfonamides onpyrethrins and rotenoids.

The concentrations of toxic agent and sulfonamide activator may bevaried as desired. it being understood, however, that the primary valueof the compounds described lies in their ability to activate thetoxicity of the plant derivatives, and therefore this value will largelydisappear if the concentration of plant derivative is too low. In thecase of pyrethrum 20:1 extract in kerosene this practical minimum isabout 1% by volume.

The following illustrates the effect on toxicity of varying theconcentration of plant extract (in this cast pyrethrum 20:1 extract) andsulfonamide (in this case p-toluene sulfonamide of reduced nitrogenbases) in a kerosene spray;

Concentration, vol.

per cent N A I D M P m Iiaiin yre rum 20:1 sulfonamide Comparison of I(3), (5) and (7') shows the amount of pyrethrum extract replaceable bythis sulfonamide without loss of toxic effect.

While the examples given herein relate to spray type compositions inwhich kerosene has been used as the solvent and dispersing agent orvehicle, it is to be understood that my plant extract-sulfonamidecombination may be used with other spreading, diluting or carryingmaterials.

I claim:

1. An insecticidal composition comprising as its principal toxicingredient pyrethrum and the benzene sulfonic acid amide from thereduced nitrogen bases from petroleum.

2. An insecticidal composition comprising as its principal toxicingredient a contact insecticide selected from the class consisting ofpyrethrum and rotenone, and an aromatic sulfonic acid amide of the typegen bases from petroleum.

ALLEN H. LEWIS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 525,821 D. R. P. May 29, 19312,268,353 ter Horst Dec. 30, 1941 OTHER REFERENCES Siegler et al.: Jr.of Econ. Entomology, vol. 35, No. 5, 1942, page 784.

